MINOR: reduce sizeInBytes for percentiles metrics (apache#8835)

Reviewers: Matthias J. Sax <[email protected]>, Guozhang Wang <[email protected]>, John Roesler <[email protected]>
kenny5he · Jun 11, 2020 · 5f7b07b · 5f7b07b
1 parent a6ca7ad
commit 5f7b07b
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Showing 3 changed files with 7 additions and 5 deletions.
diff --git a/clients/src/test/java/org/apache/kafka/common/metrics/MetricsTest.java b/clients/src/test/java/org/apache/kafka/common/metrics/MetricsTest.java
@@ -534,12 +534,12 @@ public void shouldPinLargerValuesToMax() {
     @Test
     public void testPercentilesWithRandomNumbersAndLinearBucketing() {
         long seed = new Random().nextLong();
-        int sizeInBytes = 1000 * 1000;   // 1MB
+        int sizeInBytes = 100 * 1000;   // 100kB
         long maximumValue = 1000 * 24 * 60 * 60 * 1000L; // if values are ms, max is 1000 days
 
         try {
             Random prng = new Random(seed);
-            int numberOfValues = 5000 + prng.nextInt(10_000);  // ranges is [5000, 15000]
+            int numberOfValues = 5000 + prng.nextInt(10_000);  // range is [5000, 15000]
 
             Percentiles percs = new Percentiles(sizeInBytes,
                                                 maximumValue,

diff --git a/...rc/main/java/org/apache/kafka/streams/processor/internals/metrics/StreamsMetricsImpl.java b/...rc/main/java/org/apache/kafka/streams/processor/internals/metrics/StreamsMetricsImpl.java
@@ -154,7 +154,7 @@ public int hashCode() {
     public static final String RATE_DESCRIPTION_PREFIX = "The average number of ";
     public static final String RATE_DESCRIPTION_SUFFIX = " per second";
 
-    private static final int PERCENTILES_SIZE_IN_BYTES = 1000 * 1000;    // 1 MB
+    private static final int PERCENTILES_SIZE_IN_BYTES = 100 * 1000;    // 100 kB
     private static double MAXIMUM_E2E_LATENCY = 10 * 24 * 60 * 60 * 1000d; // maximum latency is 10 days; values above that will be pinned
 
     public StreamsMetricsImpl(final Metrics metrics, final String clientId, final String builtInMetricsVersion) {

diff --git a/streams/src/test/java/org/apache/kafka/streams/processor/internals/StreamTaskTest.java b/streams/src/test/java/org/apache/kafka/streams/processor/internals/StreamTaskTest.java
@@ -529,8 +529,10 @@ public void shouldRecordE2ELatencyPercentiles() {
             task.maybeRecordE2ELatency(0L, sourceNode);
         }
 
-        assertEquals((double) p99Metric.metricValue(), 99d, 5.0);
-        assertEquals((double) p90Metric.metricValue(), 90d, 5.0);
+        final double expectedAccuracy = 0.25d; // Make sure it's accurate to within 25% of the expected value
+
+        assertEquals((double) p99Metric.metricValue(), 99d, 99 * expectedAccuracy);
+        assertEquals((double) p90Metric.metricValue(), 90d, 90 * expectedAccuracy);
     }
 
     @Test